Preparation and characterization of PEG-HPMC solid-solid phase change membrane

Solid-solid phase change hydroxypropyl methylcellulose (HPMC) membranes were prepared via blend method using poly (ethylene glycol) (PEG) as the additive. The prepared membranes were characterized using differential scanning calorimetry (DSC), thermogravimetric (TG), X-ray diffraction(XRD), transmittance, scanning electron microscope (SEM) and mechanical properties.The effect of blend ratio on the membranes properties was evaluated. The results showed that the addition of PEG would affect the thermodynamic performance of solid-solid phase change hydroxypropyl methylcellulose (HPMC) membranes. With the increase of PEG content, the heat of melting and thermal stability of membranes enhanced, whereas the breaking strength, yield strength and modulus of elasticity decreased. At the same time, the elongation at break of the composite membranes greatly improved, but the tensile strength began to decline when the amount of PEG reached 30wt%. When the addition of PEG was beyond 20wt%, the prepared membranes once transparent precipitately became opaque and opalescent.